"The worker was predisposed to develop asthma—anyone could see
that from his history of childhood allergies."
Most patients with work-related asthma do not have a history of
allergies. This is especially true for asthma caused by exposure
to low molecular weight chemicals such as isocyanates.
Isocyanates are the most common cause of work-related asthma
reported in Michigan. However, workers who have a history of
allergies are at an increased risk of developing work-related
asthma to animal dander in labs, flour in bakeries or platinum in platinum refineries.
MYTH: "It's their own cigarette smoking habits that caused their work-related asthma."
Smoking does not increase the risk of getting work-related
asthma. Some studies have found increased levels of antibodies
(Serum IgE), or shorter time to the development of asthma in
smokers. Among the patients reported in Michigan, most were not
smoking when they developed their asthma symptoms.
"The company, as well as MIOSHA reports, say they've done air
testing. All those tests came in below the MIOSHA limits. So, it
must not be work-related asthma."
Most MIOSHA workplace standards have not been developed to protect
against work-related asthma. Many workers with breathing symptoms
work in companies that meet MIOSHA standards or work with
substances that do not have a MIOSHA standard.
"A proper pre-placement screening would prevent people from being
hired into work places where they develop work-related asthma."
No combination of pre-placement testing (such as a medical
history, skin testing, or specialized breathing tests called
methacholine challenge testing) has been able to adequately
predict who will develop work-related asthma. Also, because of
the way this testing is designed, it would exclude a large number
of people from working with substances that could cause
work-related asthma, but these people would never actually develop
"Workers with asthma should just transfer to a different job in
their company, or find another job somewhere else. That would
take care of the problem."
People with work-related asthma often continue to have breathing
problems even after exposures to substances in their jobs are
reduced or they are no longer exposed to the substance at all.
The longer a person with work-related asthma continues to be
exposed to the substance, the more likely their symptoms will not
resolve even if they are no longer exposed.
"How could he develop work-related asthma now? He's been working
at that company for over ten years!"
Work-related asthma, by definition, develops after a period of
time of exposure where the person has no breathing problems. The
period of time when no symptoms are present can range from months
to more than 20 years. The beginning of work-related asthma may
happen with a change in the job, changes in the level of exposure
to an allergen, spills or other high level exposures.
"His symptoms are happening at night, not at work. So, it can't
Some people with work-related asthma do not have breathing
problems at work, but their symptoms start at night, 8-12 hours
after exposure. In
this case, the only way to find out if the breathing problems are
work-related may be to see if the person’s breathing problems get
better when they are away from work for at least two weeks.
"I know doctors are required by Michigan law to report patients
with work-related asthma. But the patient's employer will fire
him if the company is inspected because of his work-related
Inspections at the work place are done after talking with the
patient. If inspected, the patient's name is kept confidential.
No one has been fired since the State's tracking program for
work-related asthma began in 1988. Get an occupational disease reporting form.
To submit an occupational disease report for known or suspected work-related asthma, go to the MSU Occupational and Environmental Medicine website: www.oem.msu.edu. Then, on the lower right side of the web page click the orange button: Submit An On-Line Occupational Disease Report On A Patient.